An inkjet printer is a very popular printer for home computer systems. The hardware, i.e. the printer itself, tends to be very inexpensive, however, the consumables, such as ink cartridges and special paper tend to be costly. The print quality from an inkjet printer is usually at least near photographic quality (NPQ) and the speed of the device is similar to that of a laser printer.
The ink jet printer creates its output by spraying minute jets of controlled ink on the paper.
Have a look at this link to see how inkjet printers work.